In recent years, attention has been paid to a superlattice memory cell having a layered crystal (GeTe/Sb2Te3) in which GeTe layers and Sb2Te3 layers are provided between two electrodes such that the GeTe layers alternate with the Sb2Te3 layers. The resistance value of this superlattice memory cell can be changed by movement of Ge in the layered crystal. Thus, switching can be performed with a low current, and a power consumption can be reduced, as compared with a phase-change memory cell.
However, a crosspoint memory device employing superlattice memory cells is required to further reduce its power consumption, since the number of the cells is large. In particular, it is required to further reduce the power consumption in a set (write)/reset (erasure) operation on a superlattice memory cell.